1. Field of the Invention
The present invention relates to an interworking interface module for telecommunication switching systems, in particular, an interworking interface module that allows for considerable reduction in components for establishing necessary interworking connections from among an interworking terminal, a system terminal, a monitor terminal, and a tracking terminal; and an interworking interface module that realizes the simplification of the assembling procedures for a transit exchange platform.
2. Description of Related Art
An interworking interface module is normally used to interface between two telecommunication exchange systems. According to the external configuration for an equivalent model, the interworking interface module is equipped with a pair of tracking terminal I/O ports (81), a pair of terminal I/O ports (82), a pair of system terminal I/O ports (83), a monitor terminal port (84) and an indication lamp (85). With reference to the equivalent circuit of an interworking interface module shown in FIG. 9, interconnection circuitry is created in the interworking interface module, such that the I/O ports of the system terminal (83) are respectively connected to the corresponding ports of the tracking terminal (81) in a normally closed circuit. However, the I/O ports of the interworking terminal (82) are respectively connected through a resistor R2 and a switch SW1 to the corresponding ports of the system terminal (83) in a normally open circuit. When an outside terminal from another system is inserted into the interworking terminal port (82), the original connection between the corresponding tracking terminal port (81) and the system terminal port (83) is broken. By such action, the same tracking terminal port (81) through the action of switch SW1 is switched to connect to the resistor R2. The terminal resistor adds a load for the tracking terminal (81) to damp any line oscillation due to a break in line connection.
The monitor terminal (84) is connected through a resistor R3 to the circuit of the interworking terminal (82), such that the operation status of the system can be monitored provided that the system is kept under normal operation. When an outside terminal is inserted into the monitor terminal port (84), the power to the indicator lamp (85) is enabled through the action of another switch SW2, causing illumination of the indicator lamp (85).
From the foregoing description of the switch operations and the logic of the circuit in the interworking interface module, it has become apparent that the main task of the above circuit design is to provide the means for establishing line connection and switching connections from among system terminal ports, a monitor terminal port, tracking terminal ports and cross-connection terminal ports for outside systems by mechanical switch controls. In the conventional methods, large numbers of conductive wires and interconnection components are often necessary for such interconnections. Also, proper isolation procedures have to be taken to prevent mutual line interference in a high frequency signal transmission. Thus, a conventional interworking interface module provides the switching capability but with too many components and complicated procedures, for which a better way to interconnect different systems is sought.